vb.net SerialPort控件接收數(shù)據(jù)問題，用串口調(diào)試助手發(fā)數(shù)據(jù)，只有第一次可以正常接收

你定義的委托需要帶參數(shù)才行，DataReceived事件中沒有接收數(shù)據(jù)代碼，下面的代碼經(jīng)測試可用

讓客戶滿意是我們工作的目標，不斷超越客戶的期望值來自于我們對這個行業(yè)的熱愛。我們立志把好的技術(shù)通過有效、簡單的方式提供給客戶，將通過不懈努力成為客戶在信息化領(lǐng)域值得信任、有價值的長期合作伙伴，公司提供的服務項目有：申請域名、虛擬空間、營銷軟件、網(wǎng)站建設(shè)、上思網(wǎng)站維護、網(wǎng)站推廣。

Delegate Sub SetTextCallback(ByVal InputString As String)

Private Sub ShowString(ByVal comData As String)

txt_Rect.Text += comData '將收到的數(shù)據(jù)入接收文字框中

txt_Rect.SelectionStart = txt_Rect.Text.Length

txt_Rect.ScrollToCaret()

End Sub

Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived

Dim inData As String = SerialPort1.ReadExisting

Dim d As New SetTextCallback(AddressOf ShowString)

BeginInvoke(d, inData)

End Sub

如何用vb.net獲得網(wǎng)頁的源代碼

Dim url As String=" 網(wǎng)址"

Dim httpReq As System.Net.HttpWebRequest

Dim httpResp As System.Net.HttpWebResponse

Dim httpURL As New System.Uri(url)

httpReq = CType(WebRequest.Create(httpURL), HttpWebRequest)

httpReq.Method = "GET"

httpResp = CType(httpReq.GetResponse(), HttpWebResponse)

httpReq.KeepAlive = False ' 獲取或設(shè)置一個值，該值指示是否與

Internet資源建立持久連接。

Dim reader As StreamReader = _

New StreamReader(httpResp.GetResponseStream,

System.Text.Encoding.GetEncoding(-0))

Dim respHTML As String = reader.ReadToEnd() 'respHTML就是網(wǎng)頁源代碼

如何用vb.net獲取網(wǎng)頁源代碼

使用webbrowser控件來加載網(wǎng)頁，然后再

Private

Sub

WebBrowser

1_DocumentCompleted下通過使用WebBrowser1.Document.Body.

InnerHtml

來獲取網(wǎng)頁的源代碼，或使用

WebBrowser1.Document.Body.InnerText來獲取網(wǎng)頁中的文本。之后可以通過字符串控制指令或者

正則表達式

來精確獲取到你所需的數(shù)據(jù)。